Possibly he collected the professor's goods and chattels and rode off with them.

It isn't likely, though.

Cow-punchers wouldn't be apt to do all that freighting on horseback.

Would they take the trouble to balance a cot across one of their horses and ride away with it?
Or the professor's trunk?
I guess Blunt and his friends wouldn't have much use for the professor's plunder; so it's a fair surmise they didn't take it.
Some one else did, that's evident.

The testimony all points to the professor himself." "He left Gold Hill to come to Happenchance," remarked Chancy.